Pentax K-7 Sedbergh
Its weatherproof magnesium alloy shell, 5.2fps burst rate, sensitivity up to ISO6400 and Live View with HD 720p 30fps video, suggest that Pentax is aiming the K-7 at advanced enthusiasts and imaging pros, though its diminutive size is at odds with conventional wisdom. Be that as it may, where rivals cater to the high-profile press market, the K-7 has no such pretensions.
It's the most compact semi-pro DSLR camera we've seen, and smaller than the likes of the Canon Eos 50D and the Olympus E-3.
If you're coming from other brands, the layout takes some getting used to, though you'll feel at home if you're upgrading from earlier Pentax offerings. We particularly like the new graphics and layout of the rear 3in (920k dot) data panel, and it's arguably the clearest interface of any DSLR to date. That's quite something considering the K-7 has more pro-level exposure modes than rivals.
In addition to the usual priority and scene modes, the Pentax has both an Sv (sensitivity) mode and TAv (Shutter and Aperture) mode. The former allows you to adjust the ISO setting, while the camera sets both shutter-speed and aperture. The latter lets you set either the aperture or shutter-speed, and the sensitivity is adjusted to match. If there's a small niggle, it's that the shooting mode dial has a central lock button, making it a bit fiddly to change in a hurry.
The large, bright viewfinder is another plus point and, even at the semi-pro end of the market, its 100% coverage is still rare. The K-7 boasts an upgraded 11-point AF system, which seems less prone to selecting the central focus point than earlier offerings, though, we have to say the outer sensors often appeared to be selected at random.
Autofocus using Live View works a little differently to rival brands, too. An LV button close to the direction-pad is used to initiate preview, but auto-focus works only by depressing a dedicated AF button instead of the shutter-release. It works quite well in practice, but we can't see why you can't choose between the two as options.
To make matters worse, you can't easily swap between AF modes on the fly; you have to go into the main menu to switch, for example, from face detection to wide Area. And, auto-focus doesn't continuously update, unless you're pressing the AF button.
In the movie mode, which is selected from the exposure mode dial, you can only perform auto-focus before capture; after that, you have to manually focus. Still, you do have a choice over aperture selection and you can see the effect on exposure on screen. Nice touches include a sensitive level indicator, shadow and highlight warnings, real-time histogram, and a choice of colour modes; the same options available in LV mode.
From our sample clips operating noise was an issue, but the inclusion of an external Mic socket is a sensible inclusion. The built-in image stabilised sensor helps to reduce the wobbles with video, and improves image sharpness with stills when forced to use low shutter speeds. We had acceptably sharp stills at a lowly 1/8 sec with a 55mm equivalent prime.
To maximise the benefits of the K-7's waterproofing a new range of weather resistant lenses has been launched. Our review model came with the new DA 18-55mm f/3.5-5.6 WR zoom. It's a starter lens, though, and more appropriate for entry-level cameras. If you want to get the most from the K-7 sensor, you'll need to invest in some of Pentax's high grade lenses, such as the Limited range. These match the K-7's superb metal build, but aren't weatherproof.
Nevertheless, picture quality is very high. Colour rendition is even superior to the K10/20D models, and significant auto-white balance errors were rare. Noise levels were pleasingly low, too, despite cramming 14 million pixels onto an APS-C sized sensor. We felt confident using the K-7 up to ISO1600, and colours were still reasonably accurate and detail was very good. Above that, though, detail in out-of-camera Jpegs dropped off noticeably using the default (medium) Hi-ISO noise reduction settings.
A choice of Raw formats, DNG or Pentax's proprietary PEF file gives more flexibility using the bundled SilkyPix conversion software, but we didn't have the latest version of that utility available at the time of testing. However, we pulled marginally more detailed files using Adobe's Camera Raw plug-in, but while we felt ISO3200 was usable at times, the same can't really be said of ISO6400.
The K-7 is a fantastic shooter that really stands out due to its compact dimensions, build, features and superlative picture quality.
Author: Kevin Carter